All animals need ______ to convert energy from food. We get this oxygen from the air that we breathe. In order to get the oxygen into the blood where it can be transported to the rest of the body, the air travels through a system of organs called the ______ system. When you _____, air enters the body through the _______. From there it passes through the ______, and then into the ______, where the ______ is located (which prevents food from entering this tube).